| 摘要 |
A particulate matter-oxidizing material which enhances the rate of oxidizing the particulate matter at low temperatures (not higher than about 300° C.), and of which the action for purifying NOx by reduction at high temperatures (not lower than about 500° C.) is not impaired by the oxidizing action. The oxidizing material contains a cerium-zirconium composite oxide for purifying, by burning, the particulate matter in the exhaust gas from a lean-burn internal combustion engine, wherein the cerium-zirconium composite oxide contains cerium in an amount of 0.1 to 20 mol % based on the total mol number of metal atoms that are contained. Desirably, the cerium-zirconium composite oxide further contains at least one kind of metal (M) selected from the rare earth metals (excluding cerium), and the molar ratio of M/Ce is 0.1 to 10.
|
